In the related art, as a fine wiring material such as a semiconductor element formed on a substrate, aluminum or an aluminum alloy has been used. However, since the aluminum has a low melting point and poor migration resistance, it was difficult to apply to high-integration and high-speed of the semiconductor element.
Therefore, copper is recently used as a wiring material. Copper has a higher melting point and a lower electrical resistivity than aluminum, and therefore, copper is regarded as a leading LSI wiring material. However, when using the copper as a wiring material, there is a problem that it is difficult to perform microfabrication. For example, Patent Document 1 has proposed a method in which a groove is formed on an insulating layer and the copper is embedded in the groove, and then extra copper protruding from the groove is removed to form copper wiring in the fine groove.